Update Qortex API to a93a84fff164b80d81f28bf50c17f8dc3d079474

Also generate SDK with goapigen @ 6c81510db3bb4b8765ef5e5a77b2da649cbe72f0 to
fix date issues where Go's JSON serialiser won't consistently include
significant figures in the seconds field, so

32.537 => "32.537"
32.500 => "32.5"
32.000 => "32"